Table 3. Isotherm Parameters for the Adsorption of Co2+ Ions.
| pH |
|||||
|---|---|---|---|---|---|
| isotherm model | parameter | ratio AAm/Na-MMT | 3 | 4.5 | 6 |
| Langmuir |  |
1:1 | –0.011 | 0.118 | 0.158 |
| 2:1 | –0.007 | 0.142 | 0.097 | ||
| 4:1 | –0.012 | 0.107 | 0.163 | ||
 |
1:1 | –107.53 | 114.94 | 84.75 | |
| 2:1 | –222.22 | 98.04 | 108.69 | ||
| 4:1 | –103.09 | 106.38 | 97.09 | ||
| R2 | 1:1 | 0.40 | 0.81 | 0.95 | |
| 2:1 | 0.09 | 0.95 | 0.90 | ||
| 4:1 | 0.36 | 0.70 | 0.77 | ||
| Freundlich |  |
1:1 | 0.63 | 20.98 | 15.53 |
| 2:1 | 1.06 | 11.15 | 13.91 | ||
| 4:1 | 0.66 | 17.46 | 22.54 | ||
| n | 1:1 | 0.76 | 2.31 | 2.28 | |
| 2:1 | 0.82 | 1.54 | 1.72 | ||
| 4:1 | 0.75 | 2.14 | 2.61 | ||
| R2 | 1:1 | 0.96 | 0.49 | 0.72 | |
| 2:1 | 0.89 | 0.86 | 0.84 | ||
| 4:1 | 0.96 | 0.54 | 0.43 | ||